Growing a homemade crystal is a fun, simple science project that just about anybody can do! It requires some simple materials that are usually found at home, some patience, and a few days.
The first step is to assemble the necessary materials. You will need a Mason jar (or other glass jar), a measuring cup, 1 cup water, ½ cup table salt, a coarse cotton string, a pencil, a paperclip, a spoon, and a paper towel.
Next, boil the water. This can be done in the microwave or on the stove. Pour the boiling water into the Mason jar and add the salt, one tablespoon at a time. After adding each tablespoon of salt, stir the water until the salt is completely dissolved. This action will create a supersaturated solution, which means the hot water actually can dissolve more salt than cold water could, and is great for making crystals.
When the solution is complete, tie one end of the string to the paperclip and the other end to the pencil. Lower the paperclip into the saltwater solution and put the pencil across the top of the jar to make the string stand vertically in the water. Make sure the string is not too long; the paperclip should be able to pull the string straight down. Cover the mouth of the jar with the paper towel to avoid any contaminants like dust getting in the water and place the jar somewhere it will not be disturbed.
Now the active part is done! In as little as 12 hours tiny, square crystals will begin to form, and in a few days the crystals will be done. Some crystals will grow by themselves, and others will grow together with many cubes of salt together.
Salt is not the only household ingredient that grows into crystals. Epsom salts will do the same thing, although their crystals are not square but longer and sharper. Sugar and alum, too, grow into good crystals.
Once the crystal is grown, it can be preserved. Because these crystals were grown in water they can eventually dissolve a bit, especially in humid climates. Crystals will stay strong and beautiful in an airtight container. A piece of paper towel or tissue wrapped around a completely dry crystal will absorb any water that may get into the container and keep dust off the crystal.
Crystal growing is a fun activity that takes resources from around the house and turns them into a beautiful creation in just a few days. Happy growing!
Resources: http://www.sdnhm.org/kids/minerals/grow-crystal.html
http://chemistry.about.com/cs/growingcrystals/a/aa012604.htm
